#include <stdio.h>
void test1()
{
   float a=3.6;
   printf("%ld\n",sizeof(3.6));
   printf("%ld\n",sizeof(a));

}

void test2()
{
    char c=250;
    unsigned char d;
    char f;
    d=c+249;
    f=c+249;
    printf("d=%d\n",d);
    printf("d=%u\n",d);
    printf("f=%d\n",d);
    printf("f=%u\n",d);

}

void test3()
{
    double a,b,c;
    scanf("%lf %lf %lf",&a,&b,&c);
    if(a+b>c&&a+c>b&&b+c>a)
    {
        printf("YES\n");
    }
    else
    {
        printf("NO\n");
    }
}

int main()
{
    test3();
    return 0;
}